I suggest that you drop the S7 Group Stores an e-mail and ask for details - I am not sure if the new gauge is on the current Stores List. You can always hope that Paul Stokes reads this and drops you a PM! Sshh, you do not need to be too concerned about gauge narrowing on plain line track, the prototype has some side clearance bewtween the running face of the rail and the flange of the wheel - just do not try the same trick on curved track. The real problem comes with gauge narrowing at the toe of the switch - here the track gauge has to be wider than 33mm to allow for the thickness of the switch blade. Simon, you may recollect I have a handful of the sprung track gauges (see this thread)... if the screw is loosened slightly then the gap between the "gripping" flanges can be widened enough to accomodate a stock rail at one end (of the gauge) and a stock rail plus switch blade at the other end. If the stock rails are set using sprung gauges with loosened screws then the 33mm between running faces is measured between the running face of a stock rail and the running face of the opposite stock rail. Savvy? regards, Graham PW, S&C, and buffer stop.